This invention generally pertains to surgical instruments of the retractor type which are inserted into an abdominal incision and manually manipulated to displace and hold abdominal viscera whereby a surgical field of desired shape and extent is exposed and maintained. More particularly this invention relates to a type of retractor known as a Weinberg retractor being characterized by a broad, deep, metallic blade integrally formed with an elongated handle extending generally perpendicularly to the blade. The size and ruggedness of this class of retractor device are dictated by the need to reach deep into the subdiaphragmatic region to retract tissues and viscera which exhibit substantial weight and inherent resistance to displacement.
While prior art retractors of this class are generally adequate for the intended purpose of establishing an appropriate surgical field, they are not well adapted for continuous retraction during prolonged surgical procedures since the resistance to displacement displayed by the weighty mass of tissues and viscera engaged by the substantial blade surface of the retractor must be continuously overcome by a countervailing force applied to the retractor handle by the muscular effort of a surgical assistant. Therefore, rapid fatigue and acute cramping of the muscle systems of the fingers, hand and wrist are often encountered. Such discomfort may be temporarily alleviated by repositioning the hand with respect to the retractor handle or by replacement of the fatigued hand with the other hand of the operator or with the hand of another operator. However, there exists a substantial risk that the retractor will slip or otherwise release the retracted tissues and viscera back into the surgical field.
The discomfort of a retractor operator is exacerbated where the retractor blade must be continuously pulled toward the operator and simultaneously tilted or toed downwardly and toward the wall of the abdominal cavity in order to maintain a wide surgical field at considerable depth. Such tilting requires that the operator arch or cock his wrist upwardly in order to exert a downthrust and prying action near the lower tip portion of the retractor blade. This maneuver involves application of considerable force by the muscles of the wrist and forearm while adroitly avoiding traumatizing the tissues subjacent the forward end of the retractor handle as the latter is pressed downwardly and pivoted near the margin of the incision. Such careful application of substantial muscular effort is extremely tedious and tiring especially for female surgical assistants.
Another situation which often contributes to rapid operator fatigue arises where the operator cannot comfortably orient his hand and wrist with the retractor handle due to the presence of other medical personnel situated more proximate the surgical field. In this case the operator may be required to reach around or between others in an awkward fashion thereby placing additional strain on the hand and wrist performing the retracting function. Unless suitable manual leverage can be established by lengthening or articulating the handle, steady, prolonged fixation of the retractor blade is nearly impossible.
An alternative visceral retraction method involves the use of a self-retaining device of the wellknown Balfour type. The retractor blade of this type device may be mechanically positioned and held in any desired fixed position. While the fatigue-related problems recited above with respect to manually held retractors are effectively overcome by using a mechanical retractor, the greater flexibility and adaptability of a handheld retractor during the course of many surgical procedures are well understood and appreciated.
Heretofore various handle configurations have been devised to enhance gripping the handle manually. U.S. Pat. No. 659,182 issued Oct. 2, 1900, to C. J. Pilling and U.S. Pat. No. 2,829,649 issued Apr. 8, 1958, to R. J. Glenner are examples of devices provided with handle adaptations intended to provide a more positive manual grasp. However, neither of these prior art retractors recognizes or addresses the problem of operator fatigue since the strain placed on the hand and wrist muscle systems during prolonged usage is not appreciably reduced by the disclosed grip-enhancing features.